<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            position: relative;
            width: 200px;
            height: 200px;
            margin: auto;
            border-radius: 50%;
            background-color: #acacac;
        }

        .second {
            position: absolute;
            height: 1px;
            background-color: #f00;
            width: 100px;
            top: 50%;
            transform-origin: right
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="second"></div>
    </div>
</body>
<script>
    const second = document.querySelector(".second");
    setInterval(() => {
        let nowSecond = new Date().getSeconds();
        second.style.transform = `rotateZ(${6 * nowSecond}deg)`;
    },1000)
</script>
</html>